This is a fun bug. If you switch views in the same ruleset as you send the email, you get a blank email.
We use sections in a single view instead. So, one section is the "fill out" section, and the other is the "email" section. I'll use another field, usually in a secondary data source, a boolean called "IsEmailing" or something, and hide the email section if it is false, the fill out section if it is true.
Then, in my rules, I'll set IsEmailing to true, send the email and then set it back to false. Make sense?